Some of the funniest, most innovative comedy shows in recent years have added narrative continuity to self-contained conceits: Andy Daly's Review is about a critic who reviews life experiences, such as what it's like to be buried alive or to eat 15 pancakes, but it's also about how those experiences upend his life for the mission of reality television. Nathan Fielder's Nathan For You is an Extreme Makeover parody about a Canadian business school graduate who proposes radical marketing solution to revive struggling businesses, but certain characters would find their way back onto the show, and take it to strange and unexpected places. By the end of their runs, both shows developed a dense mythology, untethered to their own narrow premises.

Launched eight years ago as a podcast, before quickly ramping up as a web series for 10 seasons (and counting) on Thing X and Adult Swim, Tim Heidecker and Gregg Turkington's On Cinema at the Cinema has morphed into an even more multi-tentacled enterprise. On Cinema is ostensibly a Siskel & Ebert-style movie review show with the hosts generally divvying out ratings on a five-popcorn bag scale — though that got complicated quickly, too — but Heidecker's character keeps getting himself involved in various schemes and spinoff projects, leaving Turkington the futile task of steering segments back to movie reviews. (Or his vast collection of mediocre VHS titles at the oft-torched Victorville Film Archive.)

Heidecker, whose Abso Lutely Productions backed Nathan For You, already spun off On Cinema into the action parody Decker, also for Adult Swim, and the cult caravan rolls on with Mister America, a feature-length mock documentary that takes the series that much further afield. It's possible to enjoy the film without having seen a second of On Cinema — bits of backstory are sprinkled throughout, if not that liberally — but it rewards the most deeply invested, if only for already being attuned to its absurdist wavelength. The project is akin to "Finding Frances," the brilliant feature-length series finale to Nathan For You, but more peculiar in it obsessions and cooler around the heart.

Beyond all the in-jokes and digressions, Mister America smuggles in a trenchant critique of a political era that encourages narcissists and scam artists while driving out more sober public servants. With a documentary crew in tow, Heidecker (who uses his own name, as does Turkington) is running an independent campaign for district attorney of San Bernardino County against the incumbent, Vincent Rosetti (Don Pecchia), despite having little money, no volunteers, and a faint hope of even getting on the ballot. His only experience with the law is defending himself against multiple second-degree murder charges brought by Rosetti for selling tainted vape juice at an EDM festival. The case ended in a shocking mistrial, which Heidecker understood as a personal legal triumph and the basis for vengeful campaign against his accuser.

Heidecker's only ally in this quixotic fight is Toni (Terri Parks), who happens to be the hold-out juror that saved him from a certain guilty verdict. Toni's motives for supporting Heidecker are vaguely Trumpian —s he's concerned about "demographic change" in the area — and her social media strategy includes a Facebook page with a "testing testing testing" message, an IMDb profile, and plans to start up an Instagram account. As for Heidecker, he's canvassing the area with the anti-Rosetti sign "We have a rat problem!" (not ideal for restaurants), and promising locals a zero-tolerance, one-strike-and-you're-out policy that will eliminate all crime in the county.

The funniest scenes in Mister America revisit his ongoing feud with Turkington, who trolls his on-air partner by wearing movie promotional hats (which drive Heidecker into a rage) and imploring the documentary crew to borrow his VHS dub of The Shaggy D.A., which he sees as a metaphor for Heidecker's campaign. But the film's commitment to a vérité-style campaign doc has the effect of stripping away the jokes and focusing more on the pathology of the vile, delusional, beer-swilling dimwit at its center. Heidecker doesn't have a trace of vanity as a performer — his characters are funny, but always impossible to love — and here he seems intent on exposing rabble-rousing "populism" as a mask for self-serving ghouls.

To some degree, Mister America is a closed system, cycling through references to On Cinema enterprises and characters like Decker, Dekkar (a rock band), Heidecker's late son Tom Cruise Jr., and his hirsute anti-vax doctor Dr. San. The film is another planet in a cult universe that many viewers haven't traversed, and probably not the ideal place to visit for those curious about the On Cinema family. Yet it will nonetheless survive as a fascinating artifact of the Trump era, when the rules of politics were revised to give boors and charlatans a pathway to power — even if, like Heidecker, it's only in their own minds.